Method of chlorination



Patented lane lid,

METHOD OF CHLORIIKTA'EION.

No Drawing.

T all whom it may concern: I

Be it known that l, Josnrn Benson MAR; viN, Jrl, a citizen of the United States, and a resident of Saranac Lake, New York, have 55 invented an Improvement in Methods of (.hlorinati on, of which the following is a specification.

My invention relates to chlorination prodnets .of anthraquinone, particularly of anthraquinone' a sulphonic acid or its salts' It is the object of the present invention to prepare 1:4 dichlor anthraquinone u sulphonic acid, or salts thereof, in an economical and expeditions manner, with economy of time and materials. and with a largely increased yield over what has hitherto been obtain able. 7

In the accompanying specification I shall, by way of example, describe several illustrative embodiments of the process of my invention, it being however understood that my invention is not limited to the embodiments thereof which are herein described for purposes of illustration only.

Ret'erring to said illustrative embodiments of the present invention, I may state that it has hitherto been proposed, as in German Patent No. 216,071, example 3, to chlorinate anthraquinone a sodium sulphonate to 1: 1- dichlor anthraquinone a sodium sulphonate by dissolving the anthraquinone a sodium sulphonate in fuming sulphuric acid of about free SO content, and leading into this solution dry chlorine gas. This patent, as an example of what has hitherto been proposed inthe prior art, states that the chlorine gas shall be continued to be led into the mixture until a gain in weight of about 35% of the anthraquinone a sodium sulphonate is attained.

l have found. by actual trial and experiment, that under none of the conditions specified in the patent in question can a gain in weight of this size be achieved, and that scarcely 60% of this gain, or less than 21% increase in weight of anthraquinone a: sodium sulphonate, can be reached after fifty hours of continuous chl0rination. I have, furthermore, observed that after this amount of chlorination has been reached, the chlorination products previously produced are destroyed, if the reaction is continued.

By my process the yield'is considerably Application filed February 5, 1921.

Serial Bio. 4422,7545.

increased and the time of chlorination considerably decreased, with a consequent gain in efficiency and yield, and a substantial prevention of the destruction of the chlorination products already. produced' For this purpose I take anthraquinone a sodium sulphonate which, in the form in which it is generally prepared, contains a substantial. amount of sodium or other chlorides. Accordingly, instead of adding the oleum directly to the anthraquinone on sodium isulphonate containing sodium or other chlorides, with a consequent nonpro ductive consumption of the free S0,, 1 add ordinary or commercial sulphuric acid of a strength of about 96% to the material in question.

Upon. the addition of the sulphuric acid,

hydrochloric acid is liberated, lhe hydrochloric acid thus liberated is driven of? by any suitable means, as by passing air through the mixture of anthraquinone 0: sodium sulphonate and sulphuric acid. There is now added to this mixture an amount of oleum or S0,, to bring the free I SO, content of the mixture up to about 23%.

l have discovered that the desired reaction can be acceleratedconsiderably and the yield very materially increased by passing the chlorine into the mixture, prepared preferably as described above, under pressure. Preferably the pressure employed is from about 5 lbs. per square inch above atmospheric. pressure up to any desired pressure, such as 4- or 5 atmospheres, or more, within practical engineering limits, considering the corrosive nature of the gas involved, and this introduction and reaction chlorine may take :place within wide temperature limits.

In place of gaseous chlorine, under pressure, I may use chlorine in liquid form withinithe receptacle within which the reaction takes place, or I may generate the chlorine within such receptacle, in either of which cases the chlorine forms its own pressure within such receptacle. For exampletively satisfactory yields and results may be obtained. However, by warming the cylinders containing liquid chlorine, as, for example, to a temperature of about 60 C., and keeping the reaction vessel at a temperature of about 10 C. until sufficient liquid chlorine is introduced into the reaction vessel, a pressure of about 200 lbs. may be obtained in the reactinuvessel, whereupon it may be heated toabout 50 C. for the desired reactionto'take place. in this case far more satisfactory results and a better yield, together with a considerable econom in the use of the chlorine, may be ellecter.

This latter result may alsobe achieved by producing the chlorine in situ. from some chlorine producing substance or substances, as well as by pumping gaseous or liquid chlorine into the'reaction vessel.

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The economy in the useof chlorine effected by the above modes of procedure is considerable. For example, at apressure of about four atmospheres and with a reasonable gas space over the sulphuric acid in the reaction vessel, the chlorine used up in the reaction exceeds the theoretical. amount of chlorine required by not over 20%. @n the other hand, without pressure, as where the reaction vessel is open to the air, the re sults obtained show a consumption of ClllO rine of -from about 7 to about times the theoretical required amount of chlorine.

By chlorinating as above set forth I avoid to a large extent the formation of either the 9:10 dichlor anthracene sulpho chloride or sulphonic acids, and monochlor. c, e, or a, 6, disulphonic acids or'their sulphjif'chlorides, which are ordinarily formed in considerablequantities by the usual methods of chlorination, and which very materially diminish the yield of the desired end product, namely, 1:4 dichlor anthraquinone a sulphonic acid or its salts. Assuming a pressure of chlorination of about lbs. per square inch, and a temperature of about 30 (1., the chlorination, according to my method, will reach its maximum in less than about 2% hours, in fact, often in about only 20 hours. 1 I

The resulting product comprises a magma oisodium or other acid sulphates'andlrl dichlor anthraquinone a sulphonic acid in a mixture. of oleum and chlorsulphonic acids. The whole is now introduced into a quanity oi. Water sufficient to reduce the strength of the about 16%, by weight, of the product. This insoluble residue contains noneof the desired green-producing principle and consists almost entirely of trichlor anthraquinones. In the warm, the solution of 1:4 dichlor anthra quinone a: sodium sulpho-nate, which is the color-producing principle of the green dyestuli d-esc1'ibed and claimed in my (Bo-pend ing'patent Serial No. 442,755, filed Feb. 5,

1921, is now filtered oil from the insoluble residue, and the "filtrate is slightly acidified, as with sulphuric acid, and the 1 :4 dichlor anthraquinone 0: sodium sulphonate is salted out by adding salt until a 20% salt solution is produced. In place of a 5% solution of caustic soda, I may use a solution of equivalent strength of caustic potash or of the carbonates or'bi-carbonates of soda or potash.

The precipitated 1: dichlor anthraquinone or sodium sulphonate is now pressed, dried; and ground, and may be put to any usefor which this material is suited, as in the preparation of the green dyestuii .set forth in my co-pending application referred to above.

The advantages of the present invention have already been pointed out in some detail above.- By means of the present invention the desired reaction is accelerated so that the undesirable by-products, 9:10 dichlor anthracene sulpho chloride or sulphuric acids and monochlor a, a, or-oz, t, disulphonic acids ortheir sulpho chlorides are either notprd duced at all or are produced in such small amounts as to be unobjectionable and as not to interfere with the reaction or hell diminish the comparatively great yield render-ed Possible by my new process.

lit is of course to be understood that my invention-gig; not limited to the specific embodiments "thereof herein described for purposes of illustration only.

It is of course also to be understood that the expression sulphonic' acid appearing in certain of the claims includes also the salts of such an acid as well as the acid itself and that the expression .oleum also sulphur trioxide itself.

l claim as my invention:

1. In the process of producing 124 dichlorenthraquinone :c sulphonic acid, the step which comprises treating an anthraqu'inone ca sulphonate with sulphuric acid of astrength of about 96%, to preliminarily interact with any sodium chloride present in the anthraquinone a sulphonateyand theresubstanincludes Mill inseam after adding oleum to bring the sulphuric acid up to the desired content of free 2. In the process of producing 1 1 dichlor anthraquinone c sulphonic acid, the step which comprises treating an anthraq uinone ca sulphonate with sulphuric acid of a strength of'about 96% to preliminarily interact with any sodium chloride present in the anthraquinone a sulphonate, and thereafter adding oleum to bring'the sulphuric acid up to the desired content of about 23% free 550 '3. In the process of producing 1 :Ldichlor anthraquinone oz sulphonic acid, the step which comprises treating anthraquinone a sulphonic acid with chlorine under pressure in the presence of turning sulphuric acid.

4:. In the process of producing 1 :4 dichloranthraquinone ca sulphonic acid, the step which comprises treating anthraquinone oz sulphonic acldwith chlorine under pressure in the presence oi turning sulphuric acid of about tree SO, content.

5. In the process of producing 1 4 dichlor anthraquinone a sulphonic acid, the step which comprises treating an anthraquinone sulphonate with sulphuric acid of a strength of about 96% to preliminarily interact with any sodium or other chloride present in the anthraquinone a sulphonate, adding oleum to bring the sulphuric acid up to the desired .content of free SQ and thereafter admitting to the mixture chlorine I ,under pressure.

6. In the process of producing 1 :4 dichlor anthraquinone a sulphonic acid, the step which comprises treating an anthraquinone a sulphonate with sulphuric acid of a strength of about 96% to preliminarily interact with any sodium or other chloride present in the anthra-quinone or sulphonate,

adding oleum to bring the sulphuric acid up to the desired content of about 23% tree S@ and thereafter admitting to the mix ture chlorine 1 under pressure.

7. in the process of producing 1 4 dichlor anthraquinone a sulphonic acid, the step which comprises treating anthraquinone a sulphonic acid with chlorine under about four atmospheres pressure in the presence of fuming sulphuric acid.

8. In the process of producing-1:4 dichlor anthraquinone a: sulphonic acid, the. step which comprises treating anthraquinone a sulphonic acid with chlorine under about four atmospheres pressure in the presence of turning sulphuric acid of about 23% free SQ, content,

'9. In the process of producing 1 2 1 dichlor anthrauuinone' as: sulphonic acid, the step which comprises treating an anthraquinone a sulphonate with sulphuric acid of a step which comprises treating an anthraquinone at sulphonate with sulphuric acid of a strength of about 98% to preliminarily interact with any sodium chloride present in the anthraquinone oz sulphonate, adding oleum tobring the sulphuric acid up to the desired content of about 23% free $9 and thereafter admitting to the'mixture chlorine under about four atmospheres pressure.

11. The method which comprises the step of treating a 1:4 dichlor anthraquinonec sulphonate, containing trichlor anthraquinone, with a solution or an alkali to dissolve out the 1 :4: dichlor anthraquinone c: sulphonate from the trichlor anthraquinone, leaving the latter undissolved.

12. The method which comprises the step of treating a 1:4 dichlor anthraquinene 0: sodium suiphonate, containing trichlor anthraquinone, with a solution of an alkali to dissolve out the 1 :4 dichlor anthraquinone or sodium sulphonate from the trichlor anthraquinone, leaving the latter undissolved.

13. lhe method which comprises the step of treating a 1:41 dichlor anthraquinone ca sulphonate, containing trichlor anthraquh of treating a 1:4 dichior anthraquinone 0:

sodium sulphonate, containing trichlor an- 'il112, 111n'Oi1'I-} w th a soiution of an alkali to disso "we out the 1: 1 dichlcr ant sodium vsulpluinate our the .lor a; thraquinone, leaving: one letter ssolved. 15. The process oi": producing 1:4; dichlor anthraquinone o: sulphonic acid, whichconiprises the steps o'f'treating anthraquinone sulphonic acid with chlorine underpressure in the presence of fuming sulphuric acid,

diluting. the resulting soiution of 124i dichlor anthraquinone sul oi onic acid, salting out the 1 :i dichlor antnracuinone o; sulphonlc acid, together with trio lor anthrasuinone,

and thereafter treating the 1:4 dlchlor anthraquinone 0s sulphonic acid, to weer with trichlor anthraquinon a, with sch on of an alkali to dissolve out 1:4 dichl r 3;, quinone o: sulphonic acid from t trichlor anthraquinone, leaving the latter solved.

16. The process producing Li L dichlor anthraquinone ea sulphonic acid, which comprises the steps of tr sting anthraquinone sulphonic acid with chlorine under pressure in the presence of fuming sulphuric acid, diluting the resulting solution of i dichlor anthra'quinonrs sulphonic acid, saltin out; the lA-dichlor anthrenquinone 11 suiphunic acid, -fi;ogether With Erichlor anthmquinons, and thereafter treating the 114; dichlor 2m th'rznquinone oz sulphonic acid, mgether with.

trichlm smtln'aquinone with solutian m? am alkali to dlsmlve 011E; we 1% dIGEiLEOIfifiiIh thmquinone a: sulphanic acid fmm the Eri= ch10! mmhmquinone, leaving the latter un- Feb, 1921;.

-- JOSEPH BENSQN MARVIN, JR. 

